Various means are employed in the repair and replacement of concrete and asphalt pavement. Hard tip saws are satisfactory in certain cases but the most widely used tool is a power operated impact device such as the conventional air hammer. Such hammers are normally held and actuated individually by an operator who moves the hammer horizontally as required in the pavement breaking operation. The operation is effective with a skilled operator but is in all cases a slow and tedious procedure.
The prior art also shows apparatus employing a plurality of impact devices such as air hammers but such apparatus is not believed to be commercially available. The reason for this may be the inefficiency of a plurality of air hammers acting vertically in a gang arrangement. The hammers tend to cut individual holes and jamming, tool breakage and other difficulties are encountered in advancing a gang of vertical hammers so as to provide a swath of broken pavement as may be required in the removal and replacement of concrete on bridge decks.
It is the general object of the present invention to provide an improved apparatus employing a plurality of power operated impact devices in a gang arrangement wherein the devices may be moved progressively to efficiently provide a wide swath of broken pavement with the depth of cut closely controlled.